Adaptive optics

Adaptive optics (AO) is a suite of techniques which can be added to many microscopy modalities in order to correct sample-induced aberrations. An AO system typically includes a wavefront sensor and a corrector integrated into the main imaging path. The wavefront sensing can be either direct by using specialised sensors, or indirect via camera image analysis. The wavefront corrector can be a deformable mirror with up to several hundreds of actuators, or a liquid-crystal spatial light modulator with several millions of phase-shifting pixels. This enormous variety in degrees of freedom brings new opportunities and challenges to microscope control. With suitable control algorithms and feedback between the wavefront sensor and corrector, AO microscopes can image deeper into the tissue and maximise imaging quality by adapting the optics to the sample.